Portable heater



FIG. 1 is a perspective view taken in side elevation from one side of a portable heater embodying my design;

FIG. 2 is a perspective side elevation view taken from the opposite side of said portable heater;

FIG. 3 is a view of one side of the portable heater taken in side elevation;

FIG. 4 is a top view thereof;

FIG. 5 is a view, in side elevation, of the opposite side of said portable heater;

FIG. 6 is an elevation view of the rear end of said portable heater;

FIG. 7 is an elevation view of the front end of said portable heater; and

FIG. 8 is a bottom view thereof. 

The ornamental design for a portable heater, as shown. 